Light emitting device and method for fabricating the same

Abstract

A light-emitting device is provided. The light-emitting device comprises a light-emitting layer having a first quaternary clad layer with a first material having a first composition ratio and a second material having a second composition ratio, a second quaternary clad layer with a third material having a third composition ratio and a fourth material having a fourth composition ratio, and an activation layer contacted with first clad layer and the second clad layer between them; a first electrode electrically contacted with the light-emitting layer; and, a second electrode electrically contacted with the light-emitting layer, wherein the first quaternary clad layer and the second quaternary clad layer have a predetermined energy band gap by controlling the first, second, third and fourth composition ratio, for removing the piezoelectric field and spontaneous polarization applied to the activation layer.

1 - 21 . (canceled) 
   
   
       22 . A light-emitting device, comprising:
 a light-emitting layer having a first quaternary clad layer with a first material having a first composition ratio and a second material having a second composition ratio, a second quaternary clad layer with a third material having a third composition ratio and a fourth material having a fourth composition ratio, and an activation layer contacted with first clad layer and the second clad layer between them;   a first electrode electrically contacted with the light-emitting layer; and,   a second electrode electrically contacted with the light-emitting layer,   wherein the first quaternary clad layer and the second quaternary clad layer have a predetermined energy band gap by controlling the first, second, third and fourth composition ratio, for removing the piezoelectric field and spontaneous polarization applied to the activation layer.   
   
   
       23 . The light-emitting device according to  claim 22 , wherein the first quaternary clad layer and the second quaternary clad layer are composed of Al x In y Ga 1-x-y N. 
   
   
       24 . The light-emitting device according to  claim 23 , wherein the first material and the third material are aluminum (Al), and the second material and the fourth material are indium (In). 
   
   
       25 . The light-emitting device according to  claim 24 , wherein the first composition ratio (X) and the third composition ratio (X′) are adjusted in the range of 0<X or X′<0.4. 
   
   
       26 . The light-emitting device according to  claim 24 , wherein the second composition ratio (Y) and the fourth composition ratio (Y′) are adjusted in the range of 0<Y or Y′<0.4. 
   
   
       27 . The light-emitting device according to  claim 24 , wherein the first and second clad layers have an energy band gap of about 4.0 eV. 
   
   
       28 . The light-emitting device according to  claim 24 , wherein the first and second clad layers have an energy band gap of about 4.0 eV. 
   
   
       29 . The light-emitting device according to  claim 22 , wherein the first quaternary clad layer and the second quaternary clad layer are composed of Cd x Mg y Zn 1-x-y O. 
   
   
       30 . The light-emitting device according to  claim 29 , wherein the first material and the third material are cadmium (Cd), and the second material and the fourth material are magnesium (Mg). 
   
   
       31 . The light-emitting device according to  claim 29 , wherein the first composition ratio (X) and the third composition ratio (X′) are adjusted in the range of 0<X or X′<0.4. 
   
   
       32 . The light-emitting device according to  claim 29 , wherein the second composition ratio (Y) and the fourth composition ratio (Y′) are adjusted in the range of 0<Y or Y′<0.33.